THINK I FOUND MY VIBRATION PROBLEM

[outlaw66]

I have a vibration that starts around 1800 rpm and have been following the threads lately and searched the forum about corrections for the problem. NovaEater had one most recently. Heres what i got. To begn with I have a 160 tooth flywheel, yep thats right. The flywheel came off the 289/ 3 speed that was in the car when i got it.
I built ANOTHER 289 and installed that same 160 tooth flywheel on the recent builtup engine. I even questioned on this forum about the 160 tooth FW and did not get much feedback. D. Hearn, whom I respect a lot, even indicated in one post that Ford never had one I believe, but I also saw another post from a guy that claimed to have a 160 tooth FW.
Regardless, after assembly , the engine vibrated bad enough that I pulled the engine today and when I removed the FW, the balance weight portion of the flywheel LOOKED larger than pictures I have previously seen of a 28 oz flywheel, yet much smaller than a 50 oz. I can't seem to find any pictures now. I swear I believe this FW is my problem, yet it did not vibrate on the 289/2V engine that came in the car. Although I only drove the car about 50 miles before starting the resto.
Does anyone have a picture of the backside of a 28 oz flywheel they could post? The only number on the flywheel is C30E 6380B and another number that appears to be 6A21. I really don;t want to tear down the engine if I can determine that this is not a 28 oz FW. If its NOT a 28 oz FW, it MUST be my problem...agreed?
The vibration is definitely the engine, and not the drive train.
I think Ford slipped some weird $hit in these early mustangs because I have seen a couple of posts about FW tooth numbers that are not 157 or 164. I have a 6 bolt bellhousing (small I believe) as I could only get a 10 inch clutch on the FW. Also have a T-5.

Thanks guys..,Any comments appreciated.

Outlaw 66

 

[gsxrken]

I can't tell you what weight your flywheel has, but I have seen plenty of vibrations caused by T5 and TKO crossmembers that throw off the drivetrain/pinion angle relationship. Before you think you have a mystery flywheel, I'd verfiy your angles.

 

[outlaw66]

Thanks for the reply gsxrken, but I am positive this is an engine vibe problem. It vibrates sitting in the drive way in neutral.

Outlaw

 

[BarnStang]

Take the flywheel to a maching shop that can spin it for you. I just had two checked and they were 50oz. THey machined the weights and balanced them to 28oz for $35 each. Cheaper than new flywheels.

One of them was 41oz. And was drilled in the back multiple times. THe machinist told me that some shops will do that when they balance and blueprint an engine. THe problem with that is that if you ever change that flywheel, it will vibrate. THat flywheel can only go to that motor. He said they never do that. And they stamped 28oz on the flywheels for me so there is no mistake.

All three have to match - harmonic balancer, crank, flywheel. I even had them spin the harmonic balancer to make sure. My boss as a ton of old parts in a trailer. It's not worth the pain to have to tear it aprt again so I run that kind of stuff down to the machine shop and make sure.

THat part number sounds like a really early flywheel. C3=1963? Hard to tell what that is.

 

[65ShelbyClone]

Does anyone have a picture of the backside of a 28 oz flywheel they could post? The only number on the flywheel is C30E 6380B and another number that appears to be 6A21. I really don;t want to tear down the engine if I can determine that this is not a 28 oz FW. If its NOT a 28 oz FW, it MUST be my problem...agreed?
The vibration is definitely the engine, and not the drive train.
I think Ford slipped some weird $hit in these early mustangs because I have seen a couple of posts about FW tooth numbers that are not 157 or 164. I have a 6 bolt bellhousing (small I believe) as I could only get a 10 inch clutch on the FW. Also have a T-5.

How about this, a 28oz, 160 tooth flexplate:

 

[bnickel]

a c3 number would indicate that this came from a 63 260 v8. i seriously doubt your car came with a 63 model flywheel, so my guess is that there must be some balance difference with the early 260 v8.

 

[outlaw66]

Thanks barnstang, I may have to do that, but what I really want to do is establish EXACTLY what is causing my vibration. I'm trying to avoid tearing down a newly rebuilt engine. I searched a couple of other forums and found one guy that said the number I provided showed it was from an early Fairlane. I seem to remember seeing a picture (on this forum I think) of a 50 oz and a 28 oz flywheel backside and the weight (visually) for the 28 oz was much smaller than what I see on my 160 tooth FW. I will buy another FW no problem , I just want to be sure the FW is the problem before I re-install the engine with a different FW. I don't want to do this again.
65Shelby Clone...thanks for the flexplate pic, but it really does not help because I want to compare a TRUE (known) 28 oz FW with my FW because I believe I have more than a 28 oz but less than a 50, if thats even possible.
bnickel...there is no telling where the FW came from that was in the car. In fact, the engine MAY have been a 260 for all I know. Obvioulsy it would have been changed, but the guy I bought it from had not changed it, but the car was supposedly "restored" in the early 80s. They may have just slipped an entire engine from an early Falcon or something. 260's and 289's LOOK the same. I traded the engine (whatever it was) to a guy for a 351C, so I never really made any attempts to confirm what it was cause I didn't have any reason to do so.
Somebody out there MUST have a pic of a 28 oz FW weightside. I have a 50 oz from an 89 HO that came with my T-5 so I know what a 50 looks like, but I have not been able to obtain a pic of a 28 oz. I even went on ebay, but of course the pics on ebay only show the shiney "working" side of the FW.
Thanks for the input guys.

Outlaw

 

[outlaw66]

Anybody know if the 6A21 number on the flywheel means 66 year, January 21st?
The car is a 66 model and if the breakdown of the number as shown above is correct, this FW probably originally came on the car and is a 28 oz FW. If thats true, I'm screwed, now I'll have to tear down the engine as the vibration is probably internal. Can anyone decipher the 6A21 number that is also in raised letters below the C30E 6380B number? I can not find any 6380 FW numbers in my Ford Racing catalog, all the FW's are 6375 #'s.
Another question....if the internals were balanced and AFTERWARDS, the crank was turned .010 on the mains, would that screw up the balance bad enough to cause a vibration? Any help appreciated.

Outlaw

 

[gsxrken]

I’ve heard of the outer ring slipping on a harmonic balancer, so maybe you can check that. Perhaps the machinist scribed in the balance specs on he back of it. Or maybe the rebuilder balanced it internally and you need a zero balance flywheel. I know the FW I bought from Ford Motorsport had removable weights. Last thing is also a longshot- check your firing order, as some camshafts require the 351W/5.0 firing order. Others require the old 289/302 order.